This paper describes an evolutionarily plausible description of of a specialized working memory system involved in information management for high-order cognitive tasks through its capability for controlled maintenance and schematic access to symbolic representations. Along a volatile serially accessible symbolic storage that serves a basic maintenance function the system utilizes other accessory volatile memory systems along long-term memory (LTM) and learning systems for execution of schematic access to its content. Accessory systems can help encode the episodic information including the current state of the task and more importantly provide a means for address-based access to the content of symbolic storage. LTM and learning systems help map the current state of the task onto execution programs and thus help render schematic access and process of the retained symbolic information. Implications of this feature of the model are examined for the case if concurrent-counting task.